FIG. 18 is an application diagram showing a vehicle as a first conventional example. The vehicle A100 of the first conventional example includes a battery A110, a power switch A120, a controller A130, and a light-emitting device A140 (such as a turn lamp). The controller A130 turns ON and OFF the power switch A120 to switch the power supply path from the battery A110 to the light-emitting device A140 between a conducting state and a cut-off state, and thereby achieves simple lighting/extinguishing control of the light-emitting device A140.
On the other hand, in practical use today are such light-emitting devices for mounting on vehicles as are provided with a sequential lighting function (often called a sequential turn function or a dynamic indicator function) whereby a plurality of light-emitting elements are lit and extinguished with arbitrary timing so as to increase and decrease the area of the lit region or to move the lit region to make it appear to run.
FIGS. 19A and 19B are application diagrams each showing a vehicle as a second conventional example. The vehicle A200 in FIG. 19A includes a battery A210, a power switch A220, a controller A230, and a light-emitting device A240. The light-emitting device A240 is provided with a sequential lighting function as mentioned above, and includes light-emitting element driving devices A241(1) to (m), light-emitting elements A242(1) to (m), a microprocessor A243 for controlling the light-emitting element driving devices A241(1) to (m), a driver power supply A244 for supplying electric power to the light-emitting element driving devices A241(1) to (m), and a microprocessor power supply A245 for supplying electric power to the microprocessor A243.
On the other hand, in the vehicle A200 in FIG. 19B, the microprocessor A243, the driver power supply A244, and the microprocessor power supply A245 mentioned above are omitted from the light-emitting device A240, and in place of them, a microprocessor A250, a driver power supply A260, and a microprocessor power supply A270 are provided outside the light-emitting device A240.
FIGS. 20A and 20B are application diagrams each showing a vehicle as a third conventional example. The vehicle A300 in FIG. 20A includes a battery A310, a power switch A320, a controller A330, and a light-emitting device A340. The light-emitting device A340 is provided with a sequential lighting function as mentioned above, and includes a light-emitting element driving device A341, m light-emitting elements A342(1) to (m) connected in series, a switch driving device A343 for switching the light-emitting elements A342(1) to (m) individually between a short-circuited state and a non-short-circuited state, a microprocessor A344 for controlling the switch driving device A343, and a microprocessor power supply A345 for supplying electric power to the microprocessor A344 and the switch driving device A343.
On the other hand, in the vehicle A300 in FIG. 20B, the microprocessor A344 and the microprocessor power supply A345 mentioned above are omitted from the light-emitting device A340, and in place of them, a microprocessor A350 and a microprocessor power supply A360 are provided outside the light-emitting device A340.
An example of conventional technology related to what has been discussed above is seen, for example, in Patent Document 1 identified below.